Continued development of a biological titration microcalorimetry resulted in the first successful thermochemical analysis of amylase enzymatic digestion of starch (its substrate), as well as differentiation of nonspecific glucose oxidation from starch digestion. The results suggest that a sensitive and specific assay is available for lot-to-lot characterization of starch (and similar amylase substrate). In addition, the system was reprogrammed to allow autonomous microprocessor control. Further, methodologic and system improvements allow sensitivity improvement to a level of 5 microcalories/second within 30 seconds at a precision of plus 5 percent of C.V.